Impairment of the peripheral nervous system in Creutzfeldt-Jakob disease

BACKGROUND: The clinical manifestations of Creutzfeldt-Jakob disease (CJD) primarily reflect involvement of the central nervous system. The coexistence of CJD with peripheral nervous system involvement has also been reported. OBJECTIVE: To analyze peripheral neuron electrophysiologic changes and to compare these data with neuropathologic features of spinal motor neurons in patients with definite CJD. DESIGN AND PATIENTS: Electrophysiologic examinations were performed on 16 patients with sporadic CJD. The diagnosis was confirmed by neuropathologic examinations (15 patients) or by intravital detection of the 14-3-3 protein in the cerebrospinal fluid (1 patient). The spinal cord was neuropathologically examined in 8 patients. SETTING: Department of Clinical Neurophysiology, I Neurological Department, Institute of Psychiatry and Neurology, Warsaw, Poland. MAIN OUTCOME MEASURES: Electromyography, compound muscle and sensory nerve action potentials, distal latencies, F waves, peripheral motor and sensory conduction velocity, and spinal motor neuron numbers and morphologic characteristics. RESULTS: All patients had signs of central nervous system damage typical of sporadic CJD. Only 3 patients had clinical signs of peripheral nervous system involvement. Electrophysiologic examinations confirmed peripheral nervous system damage in these patients and revealed preclinical peripheral nervous system impairment in 11 more patients. In 1 patient, electrophysiologic examination revealed features of motor neuron disease; in 9, axonal disease; and in 4, axonal-demyelinating neuropathy. Neuropathologic examination results confirmed severe loss of spinal motor neurons in 1 patient with motor neuron disease and revealed the features of motor neuron chronic disease in 4. In 2 of them, electrophysiologic data were normal. CONCLUSION: In sporadic cases of CJD, peripheral nervous system impairment should be considered to be an integral component of disease.